GB1591448A - Systems for performing sequences of electrical tests - Google Patents

Description

(54) IMPROVEMENTS IN OR RELATING TO SYSTEMS FOR PERFORMING SEQUENCES OF ELECTRICAL TESTS (71) We, THE MARCONI COMPANY LIMITED, of Marconi House, New Street, Chelmsford, CM1 1PL, Essex, a British Company, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to systems for performing sequences of electrical tests.

More particularly the invention is concerned with systems of the kind for performing under the control of a computer a sequence of electrical tests on equipment to be tested.

One object of the present invention is to provide a novel system of the kind specified which facilitates easy compilation or modification of the computer program.

According to the present invention, a system for performing a sequence of electrical tests on equipment to be tested includes a computer, a visual display unit, and a keyboard the system being arranged to enable an operator to compile or modify a machine language computer program for any particular test by selecting by means of said keyboard each of a succession of statements from respective alternative options which are presented on said visual display unit in a high level language for each statement, the computer being arranged to derive at least part of the required machine language computer program from the selected options and to store the resulting program for subsequent use.

Preferably the system has provision for writing items into a program statement in the high level language by operation of a keyboard (which may be the previously-mentioned keyboard), such items being utilised in forming the stored program in machine language.

One example of a system in accordance with the present invention for testing complex electronic equipment will now be described with reference to the accompanying drawings in which Figure 1 shows the complete system diagrammatically, Figure 2 shows a keyboard of the system in more detail, and Figure 3 shows a visual display.

The system now to be described is arranged to carry out a succession of tests on the equipment to be tested and, at least in respect of some tests, to ascertain whether or not the result of the test falls within prescribed tolerance limits. Some examples of typical tests are given below, each test requiring appropriate power supplies and/or input signals (which may be D.C. signal or a signal having a sinusoidal or other waveform) to be supplied to the equiment:- (1 Measure the voltage at a terminal of the equipment. (The voltage measured may be D.C. or A.C. as selected).

(2) Measure the frequency of a signal appearing at a terminal of the equipment.

(3) Measure the impedance between a pair of terminals of the equipment.

(4) Measure the time for a voltage on a terminal of the equipment to reach a predeter mined value.

Referring now to figure 1 of the accompanying drawings, the system has a plurality of units 1 to 5 which are arranged selectively to be connected to terminals (not shown) of the equipment 6 to be tested by way of a reed relay switching matrix 7 and leads 8. Preferably the leads 8 are formed by one or more multi-conductor cables and conventional multi-contact connectors are provided between the cable or cables and the equipment under test to facilitate easy replacement of that equipment. Further details of the units 1 to 5 will now be given.

The programmable power supply units 1 and 2 are each arranged to supply a predetermined DC or AC voltage or current. (More than two programmable power supply units may be provided if required).

The function generator unit 3 is arranged selectively to supply either a DC signal of predetermined voltage or a signal which has a sinusoidal, triangular or square wave-form and which is of predetermined frequency and amplitude.

The test unit 4 is arranged selectively to measure DC or AC voltage or DC resistance.

The counter timer unit 5 is arranged selectively either to signal the end of a predetermined period of time or measure the time for an input voltage to reach a predetermined threshold value. Timing is effected by means of a counter responding to pulses supplied by a clock pulse generator which forms part of the unit. The unit can also be used for measuring frequency.

A programmable supply unit 9, which is similar to the units 1 and 2, is connected by way of lead 10 to the equipment 6, that is to say without passing through the switching matrix 7.

More than one such dedicated supply unit may be provided.

Electric signals to activate the appropriate unit 1 to 5 and 9 and to select the desired operating condition for the units 1 to 5 and 9 and to operate the switching matrix 7 for any particular test are supplied by a digital computer 11, these units having in known manner the necessary computer interface and, where appropriate, provision for effecting digital to analogue conversion. The result of each test (e.g. the value of the measured parameter) may be displayed to an operator on a visual display unit (not shown) and/or may be printed out by means of a line printer (also not shown).

The computer 11 has a core store 13 for storing data and programs to which immediate access is required by the computer. It also has a back-up disc store 14. The program used to control the computer 11 during a sequence of tests is in a low-level computer language which is hereinafter referred to as OSCAR.

The system under consideration has provision for an operator to construct a test program for subsequent use merely by making the sort of choices which a test engineer would be competent to make without any special knowledge of computer programming. For this purpose, the system has a keyboard 15 which has mainly alpha-numeric keys and which enables information to be entered using a high-level language (hereinafter referred to as ATLAS), an auxiliary keyboard 16 and a visual display unit 17 (which is separate from the visual display unit previously mentioned herein). The keyboards 15 and 16 and the display unit 17 may conveniently be combined into a single unit.

The manner in which the keyboard 16 and the display unit 17 are used will subsequently be described. It may however be mentioned here that the unit 17 comprises a cathode ray tube (not shown) with conventional scanning circuits (also not shown) to give a conventional television-type scan and an associated data store 18 which is arranged to store in ASCII coded form alpha-numeric characters or symbols to be displayed. The complete display consists of twenty three lines of characters and/or symbols. The stored characters are arranged to be read from the store 18 in synchronism with the display scan and the read-out signals are utilised in known manner to control a character generator 19 which supplies the required video signal to the cathode ray tube of the unit 17. Each character location on the cathode ray tube screen has associated with it eight bits of storage in the store 18 of which seven bits are used to characterise the character, if any, to be displayed. When the eighth bit is set, the displayed character is presented in reverse form in that it appears as a black character against a light background in place of the normal white against a dark background. Such reverse presentation of a character, or group of characters, is utilised as a cursor on the display.

The manner in which the apparatus described above may be used to compile a test program will now be described. The complete program consists of a series of statements and each statement is composed mainly of items selected from one of a plurality of standard "profiles", in some cases with the addition of other items or information. When composing a statement, the appropriate profile is displayed by the display unit 17 and the required items to make up the statement are selected by means of the auxiliary keyboard 16. Each statement comprises a test number (01, 02, 03 etc., as allocated by the computer 11), an appropriate verb (e.g.

CONNECT or CALCULATE taken from a predetermined list of verbs) and one or more items identifying the apparatus to which the verb applies and/or specifying details of the operation identified by the verb.

The first step in compiling a test program is for the operator to type a characteristic group of letters (e.g. MOIRA) on the keyboard 15. This causes the necessary program modules (i.e.

"software" routines) associated with all the profiles (e.g. allocating data storage and for the text-in facility which will subsequently be described) to be loaded into the core store 13 from the disc store 14. In addition, information is transferred to the core store 13 in respect of the following first profile which is displayed by the display unit 17.

TEST PROGRAM FILES MODE FILE NAMES ENTER 1 (6) COPYTOWF 2 7 COPYTOMF 3 8 CREATE 4 9 DELETEWF 5 (10) Referring now also to Figure 2 of the accompanying drawings the display cursor (as previously described) is called up by operation of the key 20 of the auxiliary keyboard 16.

Upon operation of this key, the appearance of the word ENTER in the display (i.e. the first word in the left hand column from which a selection is to be made) is changed to reverse form so as to constitute a cursor. The vertical position of the cursor may be changed, in either direction by operation of keys 21 and 22 of the keyboard 16 and one or other of these keys is operated whenever a selection is to be made so as to bring the word which it is required to select into reverse form. Since, in the circumstances now under consideration, it is required to create a new program file, the key 22 is pressed three times so that the word CREATE is in reverse form. The next operation is to generate and store a name for the file. This is done by pressing the key 23 of the keyboard 16 (which causes a mark" > " to appear at the bottom of the display) and typing on the keyboard 15 first a characteristic group of characters (e.g.

DOS) to signify that text is to follow and then the required name of the newly executed file followed by the character $. Initially the typed-in name appears at the bottom of the display (opposite the " > " mark) and, if in error, may be corrected in known manner prior to typing the character g. Upon the character $ being typed on the keyboard 15 (signifying that the name has been completed) details of the name, which at this time is stored in the core store 13, is written into the master file in the disc store 14. Simultaneously the name is transferred in the display alongside the number of the next available file. (The ability to write text into a displayed profile in the manner just described is herein referred to as the "text-in" facility).

A key 24 of the keyboard 16 is operated to move the cursor to the right until it reaches the appropriate column of the file number and the key 21 or the key 22 is then operated to cause the cursor to mark the required program file. (Each operation of the key 24 causes the cursor to move one space to the right. For more rapid traverse, a key 25 may be used to move the cursor eight places to the right. Although not used here, it is convenient at this time to refer to keys 26 and 27 which respectively cause the cursor to move one and eight places to the left).

Upon the key 23 then being pressed and DOS typed as before, "ARE YOU SURE? YES/NO" appears at the bottom of the display. Assuming the answer is "yes", "YS" is typed on the keyboard 15 and this causes a line of dashes to appear on the display against the work file indicator WF. After a few seconds during which the new program file information is transferred from the master file in the disc store 14 to a work file in the disc store 14, (this operation involving the information first being transferred from one section of the disc store 14 to the core store 13 and then being transferred from the core store 13 to another section of the disc store 14) the file name appears alongside the work file indicator WF and the cursor is automatically moved to mark the word ENTER. Again the key 23 is pressed and DOS typed and this causes a new profile to be displayed by the unit 17 as follows: BEGIN

BEGIN, ATLAS, PROGRAM - 91 $ I I l PROGRAM NUMBER The cursor is called up by pressing the key 20 of the keyboard 16; it appears to the right of the program number. Using the test-in facility, a description of the program is inserted in the space marked by the cursor. The key 28 is then pressed and this causes the work file in the disc store 14 to be updated accordingly, an indication (e.g. the appearance of a characteristic letter), being given on the display when that has occurred. The cursor disappears on typing X so that the inserted description is then in non-reverse form. Finally typing 00 causes an index of available profiles to be displayed by the unit 17 in which each profile has a characteristic number of two decimal digits.

Any selected profile may be displayed by the unit 17 at any time merely by typing the appropriate profile number on the keyboard 15. (In this context the profile index may be considered as a profile having the number 00).

Successive statements of the test program are built up using selected profiles and the way in which this is done with some typical profiles will now be described.

For setting up programmable power supply 1, the following profile is displayed: PROGRAMMABLE POWER SUPPLY 1 VOLTAGE CURRENT SET UP POWER SUPPLY 1000.000 MVDC 000.000 MADC R01 VDC ADC ON S OFF The key 20 is pressed to call up the cursor which first appears at the voltage value which is initially 000.000. If a voltage is to be inserted here, it is inserted using the text-in facility. The alternative, as selected by movement of the cursor by means of the key 22, is a voltage value stored by a register ("R01") of the computer 11. (The computer 11 may have a plurality of other registers which may be used in similar manner. Although R01 appears in the profile as initially displayed, another register may be selected by overwriting R01 with the identity (e.g.

R05) of the required register using the text-in facility). Upon a selection being made, the displayed profile is automatically changed to show the new selection. The key 20 is then reoperated to cause the cursor to move to the right to the next column to enable either MVDC (i.e. milli-volts DC) or VDC (i.e. volts DC) to be selected as before. If the power supply unit in question is being set up to supply a predetermined voltage, as has been assumed, no entry is made in the two columns headed CURRENT and accordingly the cursor is moved through those columns by operation of the key 22 so that it marks ON. (In the event of the unit being required to supply a predetermined current rather than voltage, the two VOLTAGE columns would be passed through and entries only made in the two CURRENT columns).

It may be mentioned here that, as the cursor is moved to each of the five columns in turn, it appears in each column in the position most likely to be used. These positions are shown in the above profile by two horizontal lines although those lines would not, of course, appear in the profile as displayed.

It is convenient to mention here that whenever the cursor appears on a displayed profile, the identity of the item selected by the cursor is written into the core store 13 in OSCAR. The effect of moving the cursor vertically in a column of a displayed profile is accordingly to change the OSCAR information stored by the core store 13 with the result that, when the curso is moved on to the next column, information in respect of the last cursor-marked item of the preceding column is retained in store. In other words, apart from possible use of the text-in facility, operation of the keys 21, 22 and 24 to 27 is all that is required to compile a statement in ATLAS from a displayed profile, information in respect of that statement being stored in the core store 13 in OSCAR.

When all the selections to complete a statement have been made a key 29 of the keyboard 16 is pressed. This causes the statement, which at this time is stored in the core store 13 to be written into the work file in the disc store 14 in OSCAR.

For setting up the function generator 3, the following profile is displayed: FUNCTION GENERATOR SET UP, FUNCTION GENERATOR, MODE CONTINUOUS NO OUTPUT FUNCTION, SQUARE, FREQUENCY 0001.0000HZ, TRIANGULAR KHZ SINE AMPLITUDE, 0001.000 Volts g R01 In this case the statement is composed in essentially the manner previously described by selecting by means of the cursor the mode (i.e. supplying an output or no output), function, frequency, frequency range, and amplitude in turn. When the selection has been completed, the key 29 is pressed.

For setting up the test unit 4, the following profile is displayed: TEST UNIT SET UP, TEST UNIT, VOLTS AC, .1 , g READ VOLTS DC 1 MEGOHMS 10 KILOHMS 100 1000 VDC S When composing a statement involving the test unit 4, the procedure is essentially as previously described and merely involves selection of SET UP or READ, one of the four tests to be carried out and one of five ranges of value prior to pressing the key 29. (There may be a program subroutine to ensure that certain combinations, e.g. megohms with a high multiplication factor, are not selected). It will be noted that in this case there are no preferential positions for the cursor and accordingly the cursor starts in each of the three columns at the top position. When the statement includes READ, the result is temporarily stored by a register of the computer 11.

For effecting a connection through the reed relay switching matrix 7, the following profile is displayed: CONNECT/DISCONNECT CONNECT TEST UNIT + DISCONNECT TEST UNIT POWER SUPPLY 1 + , TER NO , ,g POWER SUPPLY 1- GROUND POWER SUPPLY 2 + ALL POWER SUPPLY 2 COUNTER FUNCTION GEN If a statement is composed using the profile involving connection to a specified terminal of the equipment under test, TER NO is selected in the third column by means of the cursor and the relevant terminal number is added using the text-in facility. It may be mentioned here that although a statement to disconnect all connections to a unit is valid, a statement involving CONNECT and ALL cannot properly be made and a computer subroutine is provided to prevent such a statement being entered.

It is to be understood that many other profiles are available for display and use in composing statements. These include statements involving calculations by the computer 11, display of measurements made by the test unit 4, timing wait periods by means of the counter/timer 5, comparison of measured quantity with tolerance limits, instructions as to next program (GO TO) etc.

After a series of connect statements have been composed, the operator can call up a display on the unit 17 to show the cross points of the switching matrix 7 that are then desired to be operated. This is done by typing C on the keyboard 15. A typical display is shown in Figure 3 of the accompanying drawings. (It may be mentioned here that, when composing a CON NECT statement, a sub-routine automatically selects the appropriate reed relays which are required to be operated to effect the desired connection).

When a test program has been completed, a FINISH profile is called up and entered, by means of the key 29, without amendment or selection.

At any time during the compilation of a test program, the operator can obtain a display on the unit 17 of up to fourteen of the ATLAS statements already composed. This is done by typing the letter M on the keyboard 15. Alternatively, or in addition, all the statements composed to date can be printed out by a line printer (not shown) by pressing another appropriate key of the keyboard 15.

One typical example of a complete test program, as printed out by a line printer in the manner just described is given below: 1234 TEST BEGIN, ATLAS PROGRAM, 1234 TEST S 123400 SET UP POWER SUPPLY 1, VOLTAGE 15.000 VDC s 01 SET UP, TEST UNIT, VOLTS DC, 100 S 02 WAIT FOR, 50 MSEC g 03 CONNECT, POWER SUPPLY 1 TER 65 $ 04 CONNECT, POWER SUPPLY 1, TER 33 S 05 CONNECT, TEST UNITS + , TER 45 S 06 CONNECT, TEST UNIT - , TER 61 X 07 READ, TEST UNIT, VDC s 08 DISPLAY, MEASUREMENT, VDC F 999900 FINISH , The complete test program is finally transferred from the work file (WF) to the master file (MF) in the disc store 14 by use of the TEST PROGRAM FILES profile. The program stored in the master file may then be used to carry out the test in question by typing R on the keyboard 15.

The system under consideration has provision for changing a test program by amending an existing statement, deleting an existing statement or adding a new statement. In order to do so, it is necessary first to transfer the program from the master file to the work file. Then to amend an existing statement, for example, the statement in question is transferred from the work file in the disc store 14 to the core store 13 and the desired change is effected using the appropriate profile displayed on the unit 17. The amended statement is entered in place of the existing statement by pressing the key 28 of the keyboard 16. The original (unamended) statement may be restored by pressing the key 30.

It is to be understood that data defining each profile is permanently held in the disc store 14. When any particular profile is to be displayed in the manner described herein, the data for that profile together with associated sub-routines are written into the core store 13. Similarly program modules for translating from ATLAS to OSCAR (to enable an ATLAS statement composed off-line to be entered) and from OSCAR to ATLAS (to enable a print-out in ATLAS to be obtained of a stored test program) are permanently resident in the disc store 14 and when needed are written into the core store 13 to enable a required translation to be effected under the control of the computer 11.

WHAT WE CLAIM IS: 1. A system for performing a sequence of electrical tests on equipment to be tested said system including a computer, a visual display unit, and a keyboard, the system being arranged

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (18)

1. **WARNING** start of CLMS field may overlap end of DESC **.

   If a statement is composed using the profile involving connection to a specified terminal of the equipment under test, TER NO is selected in the third column by means of the cursor and the relevant terminal number is added using the text-in facility. It may be mentioned here that although a statement to disconnect all connections to a unit is valid, a statement involving CONNECT and ALL cannot properly be made and a computer subroutine is provided to prevent such a statement being entered.

   It is to be understood that many other profiles are available for display and use in composing statements. These include statements involving calculations by the computer 11, display of measurements made by the test unit 4, timing wait periods by means of the counter/timer 5, comparison of measured quantity with tolerance limits, instructions as to next program (GO TO) etc.

   After a series of connect statements have been composed, the operator can call up a display on the unit 17 to show the cross points of the switching matrix 7 that are then desired to be operated. This is done by typing C on the keyboard 15. A typical display is shown in Figure 3 of the accompanying drawings. (It may be mentioned here that, when composing a CON NECT statement, a sub-routine automatically selects the appropriate reed relays which are required to be operated to effect the desired connection).

   When a test program has been completed, a FINISH profile is called up and entered, by means of the key 29, without amendment or selection.

   At any time during the compilation of a test program, the operator can obtain a display on the unit 17 of up to fourteen of the ATLAS statements already composed. This is done by typing the letter M on the keyboard 15. Alternatively, or in addition, all the statements composed to date can be printed out by a line printer (not shown) by pressing another appropriate key of the keyboard 15.

   One typical example of a complete test program, as printed out by a line printer in the manner just described is given below:

   1234 TEST BEGIN, ATLAS PROGRAM, 1234 TEST S

   123400 SET UP POWER SUPPLY 1, VOLTAGE 15.000 VDC s

   01 SET UP, TEST UNIT, VOLTS DC, 100 S

   02 WAIT FOR, 50 MSEC g

   03 CONNECT, POWER SUPPLY 1 TER 65 $

   04 CONNECT, POWER SUPPLY 1, TER 33 S

   05 CONNECT, TEST UNITS + , TER 45 S

   06 CONNECT, TEST UNIT - , TER 61 X

   07 READ, TEST UNIT, VDC s

   08 DISPLAY, MEASUREMENT, VDC F

   999900 FINISH , The complete test program is finally transferred from the work file (WF) to the master file (MF) in the disc store 14 by use of the TEST PROGRAM FILES profile. The program stored in the master file may then be used to carry out the test in question by typing R on the keyboard 15.

   The system under consideration has provision for changing a test program by amending an existing statement, deleting an existing statement or adding a new statement. In order to do so, it is necessary first to transfer the program from the master file to the work file. Then to amend an existing statement, for example, the statement in question is transferred from the work file in the disc store 14 to the core store 13 and the desired change is effected using the appropriate profile displayed on the unit 17. The amended statement is entered in place of the existing statement by pressing the key 28 of the keyboard 16. The original (unamended) statement may be restored by pressing the key 30.

   It is to be understood that data defining each profile is permanently held in the disc store 14. When any particular profile is to be displayed in the manner described herein, the data for that profile together with associated sub-routines are written into the core store 13. Similarly program modules for translating from ATLAS to OSCAR (to enable an ATLAS statement composed off-line to be entered) and from OSCAR to ATLAS (to enable a print-out in ATLAS to be obtained of a stored test program) are permanently resident in the disc store 14 and when needed are written into the core store 13 to enable a required translation to be effected under the control of the computer 11.

   WHAT WE CLAIM IS: 1. A system for performing a sequence of electrical tests on equipment to be tested said system including a computer, a visual display unit, and a keyboard, the system being arranged

   to enable an operator to compile or modify a machine language computer program for any particular test by selecting by means of said keyboard each of a succession of statements from respective alternative options which are presented on said visual display unit in a high level language for each statement, the computer being arranged to derive at least part of the required machine language computer program from the selected options and to store the resulting program for subsequent use.
2. 2. A system according to Claim 1 wherein there is provision for writing items into a program statement in the high level language by operation of a keyboard, such items being utilised in forming the stored program in machine language.
3. 3. A system according to Claim 1 or Claim 2 wherein said computer is arranged to operate at any time under the control of an immediate access store and information in respect of a plurality of profiles for display by said visual display unit, each such profile comprising the alternative options from which a statement may be selected as aforesaid, is permanently stored in a back-up store in machine language, information in respect of each profile being temporarily written into the immediate access store whenever that profile is to be displayed by the visual display unit.
4. 4. A system according to Claim 3 wherein said back-up store also contains information for translating between said high level language and said machine language, this information being temporarily written into the immediate access store when such translation is required.
5. 5. A system according to Claim 3 or Claim 4 wherein said immediate access store is a core store.
6. 6. A system according to Claim 3, Claim 4 or Claim 5 wherein said back-up store is a magnetic disc store.
7. 7. A system according to any preceding claim wherein the system also includes a plurality of units for connection to equipment to be tested each of these units being adapted so that operating conditions thereof and/or test parameters are set when a test is to be carried out by signals supplied by said computer.
8. 8. A system according to Claim 7 wherein one of said units is a power supply unit.
9. 9. A system according to Claim 8 wherein said power supply unit is adapted selectively to supply either a predetermined voltage or a predetermined current.
10. 10. A system according to Claim 7 wherein one of said units is a function generator which is adapted to supply a signal having a required waveform.
11. 11. A system according to Claim 10 wherein said function generator is adapted to supply a signal having a waveform selected from one of a plurality of waveforms, a predetermined amplitude and a predetermined frequency.
12. 12. A system according to Claim 7 wherein one of said units is a test unit which is adapted to measure the voltage of a signal supplied by equipment under test.
13. 13. A system according to Claim 12 wherein said test unit is adapted to measure voltage which is selectively either AC or DC.
14. 14. A system according to Claim 7 wherein one of said units is a test unit which is adapted to measure resistance.
15. 15. A system according to Claim 7 wherein said units comprise a power supply unit as specified in Claim 8 or Claim 9, a function generator as specified in Claim 10 or Claim 11 and a test unit as specified in both Claim 12 and Claim 14.
16. 16. A system according to any one of Claims 7 - 15 wherein a switching matrix is arranged selectively to connect at least some of said units to equipment to be tested, the connections effected by the matrix for any particular test being determined by signals supplied by said computer.
17. 17. A system according to Claim 16 wherein said switching matrix is a read relay matrix.
18. 18. A system for performing a sequence of electrical test on equipment to be tested substantially as hereinbefore described with reference to the accompanying drawings.